1. Field of the Invention
The present invention relates to an apparatus and a method for creating melody pieces and rhythm patterns to be suitable for an automatic music composing apparatus and method, and a machine readable medium containing program instructions for realizing such an apparatus and a method using a computer system, and more particularly to an apparatus and a method capable of extracting a rhythm pattern from a given melody motif and creating melody pieces based on the extracted rhythm pattern and on similar and/or contrastive rhythm patterns, thereby producing a melody with good similarity or good contrast to the given motif melody or producing a rhythm pattern with good similarity or good contrast to the given rhythm pattern. The invention is applicable in various kinds of electronic musical apparatuses such as an electronic musical instrument, an automatic music composing apparatus, and a computer-system-configured music composing apparatus.
2. Description of the Related Invention
The same inventor has previously proposed an automatic music composing apparatus and method for generating melody data of an amount of a tune by inputting a theme melody and extracting from the stored data base such melody generating data that represent the same or similar melody characteristics (or melody itself) as the inputted theme melody, and constructing a melody based on thus extracted melody generating data, and applied for a patent in the U.S. PTO (Ser. No. 09/212,192), which is pending in the U.S. PTO and does not constitute prior art against the present invention. The previous invention is capable of generating a melody which fits the theme melody and has abundant ups and downs.
In the above proposed automatic music composing apparatus, a melody piece for a sentence A' which is similar to a sentence A is obtained by: 1) copying (to be identical) or imitating (to be similar) the first (or second) half melody fraction of the sentence A and paste it to the first (or second) half of the sentence A' and newly creating a melody fraction for the second (or first) half (i.e. the remainder) of the sentence A'; 2) shifting the pitches of the notes in the melody piece of the sentence A to make a melody piece for the sentence A'; and so forth.
Further, a melody piece for a sentence B which is contrastive to a sentence A is obtained by: 3) pitch-inverting the melody of the sentence A with respect to a certain reference pitch to make a melody for the sentence B (e.g. a melody with notes C, D, E and G is inverted into a melody with notes E, D, C, A with respect to the pitch D); 4) changing the density (sparse or dense) distribution of the note in terms of rhythm in the sentence A to make a melody for a sentence B (e.g. in case the note distribution in the first half of the sentence A is sparse and that in the second half of the sentence A is dense, the note distribution for the first half of the sentence B is made dense and that for the second half of the sentence B is made sparse); and so forth.
According to the method 1) above, a newly created melody piece for the second (or first) half of the sentence A' may not always assume a good matching to the copied or imitated melody piece for the first (or second) half of the sentence A'. According to the method 2) above, a pitch-shifted melody from the melody of the sentence A may not highly assume the characteristic features of the original melody. Thus, the obtained melody for the sentence A' may sometimes assume poor musical similarity to the melody of the sentence A.
According to the method 3) or 4) above, a pitch-inverted melody or a note-density-changed melody from the melody of the sentence A may be well different from the original melody of the sentence A but may not always assume a musically good contrast to the melody of the sentence A to be a melody for the sentence B.